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Energy Chat
The Invisible Cost of Energy
Ever wondered where your electricity comes from? What are the origins of the invisible force powering your iPhone and allowing you to have YouTube at your constant disposal? Sixty-four percent of American electricity comes from fossil fuels (coal 43%, natural gas 22%, petroleum 1% [1]). The other 36% comes from nuclear, hydroelectric, and other renewable sources. This means 64% of the charge in your battery comes from these carbon-rich energy sources. I am not here to educate you on how burning fossil fuels creates electricity. I am here to talk about some of the unfortunate byproducts of this relentless burning.
Coal (the number one offender) is formed over many years when heat and pressure decompose organic material like plants. Burning coal releases carbon dioxide, sulfur dioxide, nitrogen oxides, and mercury compounds into the atmosphere. The average emission for coal in the U.S. is-
- 2,248 lbs/MWh of CO2
- 13 lbs/MWh of SO2
- 6lbs/MWh of nitrogen oxides [2].
For reference, one MWh (Megawatt hour) is equal to the electricity used by 330 homes in one hour.
While the contribution of SO2 and NOx gases may seem small in comparison to CO2, they pack a punch with respect to their affect on our environment. Nitrogen oxides cause smog, which burns lung tissue, and makes people more susceptible to chronic respiratory diseases. Next time you see a smog alert understand that it is not only from the burning of gasoline, but also from industrial coal burning. Sulfur dioxide is a chief contributor to acid rain, causing acidification of rivers, lakes, and streams. It also aggravates respiratory and cardiovascular problems [3].
Lastly, carbon dioxide has been increasing in the earth’s atmosphere since the industrial revolution. For all the naysayers out there, pay attention. Fossil fuels contain mainly carbon. When they are burned they react with oxygen and produce carbon dioxide. I know, common sense, keep reading. Light energy from the sun arriving at the earth has wavelengths shorter than 4,000 nm. Carbon dioxide in our atmosphere is not able to absorb these small wavelengths of energy. Therefore, energy from the sun passes through the atmosphere and reaches earth where it is absorbed and thus heats the planet. Here is where it gets interesting; heat energy from the earth has wavelengths greater than 4,000 nm, which CO2 can absorb. When heat leaves earth it is absorbed by the CO2 in the atmosphere. This sends CO2 into an unstable state, and to stabilize it releases the energy it just absorbed, but some of this energy is sent back to earth and some is sent out to space [4]. This next figure from the Schlumberger (world’s largest oilfield services company) educational website shows this process. From the Schlumberger website they state, “There is a clear relationship between atmospheric CO2 concentrations and global temperature.”
Figure 1. CO2 molecules trapping heat energy and sending the heat out in all directions [7].
As seen above, CO2 is trapping heat from our own earth and sending it back down to us, hence the greenhouse effect. If you do not believe me, look up how carbon dioxide works yourself. This graph from the NOAA shows the trend of increasing CO2 in the atmosphere.
Figure 2. Chart shows increase of atmospheric carbon dioxide [5].
Not only is the atmosphere paying for this abundance of CO2, so are the oceans. The NOAA states in their May 2008 State of Science Fact Sheet that the oceans have absorbed 50% of the carbon dioxide released from burning fossil fuels, resulting in chemical reactions that lower the pH of the ocean. This has caused an increase of the Hydrogen Ions in the ocean leading to the acidification of our oceans. Ocean acidification slows down the rate at which corals, marine algae and free-swimming zooplankton produce and maintain their skeletons. Also, studies have indicated that this acidification has adverse impacts on the survival of larval marine species, including commercial fish and shellfish [6].
Burning coal to produce electricity is the single biggest man-made contributor to atmospheric carbon dioxide in the world [1]. Just because electricity “looks” clean, do not be fooled.
Citations
[1] U.S. Energy Information Administration. Coal Explained. Energy Explained. [Online]. Available: http://www.eia.gov/energyexplained/index.cfm?page=coal_environment
[2] U.S. Environmental Protection Agency. Coal. Clean Energy. [Online]. Available: http://epa.gov/cleanenergy/energy-and-you/affect/coal.html
[3] A.H. Lockwood et al., “Coal’s Assault on Human Health,” Physicians for Social Responsibility.
[4] NASA Earth Observatory. Climate Forcings and Global Warming. [Online]. Available: http://earthobservatory.nasa.gov/Features/EnergyBalance/page7.php
[5] NOAA. Atmospheric CO2 at Mauna Loa Observatory. [Online]. Available: http://www.esrl.noaa.gov/gmd/webdata/ccgg/trends/co2_data_mlo.pdf
[6] NOAA. Ocean Acidification. State of the Science Fact Sheet. [Online]. Available: http://oceanservice.noaa.gov/education/yos/resource/01state_of_science.pdf
[7] Schlumberger Excellence in Education Development. CO2 and Temperature Change. Global Climate Change and Energy. [Online]. Available: http://www.planetseed.com/relatedarticle/co2-and-temperature-change
Facts and Figures about Energy Supply
Have you heard about global warming? Dumb question, of course you have. Have you seen numerous charts about global warming and wanted to be convinced, but walked away confused? Me too. I myself have been inundated by large amounts of data making a case for man made global warming and I want to believe it, but I see no consistency and get a gut feeling that everyone is trying to push their own agenda. As with most things in life, it will take time before we are able to look back and get to the truth of the matter. In the mean time though, there are actual problems to solve. So, if you’re not one for speculating and want to solve actual problems, read on.
Our country runs on fuels that are going to run out in the near future. These fossil fuels consist of natural gas, oil, and coal. Here are the facts:
- As of 2013, there were 2,203 trillion cubic feet (TcF) of technically recoverable natural gas remaining in the U.S. In 2013 the U.S. consumed approximately 24 TcF. At that rate we have 92 years remaining on our own supply of natural gas (1).
- As of 2012, using current mining technologies, there were 257.6 billion short tons of recoverable U.S. coal. In 2012 the U.S. used 1.02 billion short tons of coal, leaving us with 253 years of coal at that rate. The EIA predicts we actually have 180 years left, at the current production growth. The U.S. has 27.3% of the worlds coal reserves (1).
- According to the EIA in 2013 there were 1,645 billion barrels of proved crude oil reserves. In 2013 the world consumed approximately 33 billions barrels of oil. At this rate we have about 50 years of crude oil left (2). BP says we have 53.3 years left.
Why wait for this problem to smack us in the face before solving it? This graph shows that energy consumption is not slowing down. Look close, the EIA predicts that by 2040 both India and China will be using twice as much energy as they are now.
This type of outlook should make entrepreneurs salivate! Every single fossil fuel powered motor in this world will someday have to be replaced. Think of the opportunity, by the time you retire in 50 years you could be sitting pretty. Also, new forms of energy production will have to be embraced to satisfy our love of electronic devices.
Secondly, renewable energy industries require more man-power, which in turn will create more jobs. Think of how many people you know that work at the local power plant. Do you even know where the local power plant is? Most energy companies run off of heavy machinery and are largely automated. They are centralized in one location and feed power all over a state. Alternative energy requires local power production sites and maintenance, bringing jobs and entrepreneurial opportunities to each community. Residential solar installation is a good example of this. This type of business requires a local company to install solar panels on a house and requires periodic maintenance, at the same time allowing customers to rely less on the grid, saving on electricity bills.
Lastly, renewable energy implies price stability. There is no impending countdown on when the sun will stop shining or the wind will stop blowing. Selling a product with that kind of marketability is every business mans dream. With a diverse portfolio of technologies (solar, wind, hydro), you are not as dependent on one and can provide more stable power.
Imagine the possibilities, solar powered skyscrapers, ships, cars, generators. Wind fields feeding into the power grid supplying a towns full energy needs. We may not be there yet, but 120 years ago no one believed that man could fly, let alone land on mars. We, as students at Georgia Tech have an obligation to the Southeast and our country to look into this topic, regardless of political leanings. Today there are bigger obstacles to alternative energy than the technical ones. Nevertheless, this earth we all live on has finite resources and when these fossil fuels run out we will need new sources of energy to supplement them. When jumping out of a plane would you wait until you hit the ground to pull the parachute? If we let ourselves hit the ground will we still be able to pull our ‘parachute’?
Citations
[1] U.S. Energy Information Administration. International Energy Outlook 2013. Energy Explained. [Online]. Available: http://www.eia.gov/energyexplained/index.cfm
[2] U.S. Energy Information Administration. Energy Explained. US Primary Energy Consumption 2015. [Online]. Available: http://www.eia.gov/energyexplained/index.cfm
[3] U.S. Energy Information Administration. International Energy Statistics. Total Oil Supply. [Online]. Available: http://www.eia.gov/forecasts/ieo/pdf/0484(2013).pdf
About the Author
My name is Zach Archambault and I am Electrical Engineering student at Georgia Tech. I am interested in electrical energy, electromagnetics, and electronic design and applications. I have a new found fascination for energy harvesting and am exploring the possibilities there. Feel free to contact me at zarchambault3@gatech.edu
Energy Chat: Solid Oxide Fuel Cells
Sooooo…. what’s a fuel cell?
A fuel cell is kind of like a battery. Both have a cathode, electrolyte and an anode and can be used to power an external load. The biggest difference is that instead of a fixed amount of energy that a battery holds, a fuel cell can keep generating power as long as you feed it a fuel gas, which can be hydrogen or larger hydrocarbons like methane or propane in some cases. In most cases, the energy is generated by oxidizing the hydrogen fuel resulting in the formation of water.
Figure 1. Fuel cells are categorized by the electrolyte used to conduct the ionic species.
There are several different types of fuel cells that are characterized according to the electrolyte used and the mobile ionic species. Most fuel cells use a liquid electrolyte, which has a higher conductivity capable of delivering a higher power output. Low temperature fuel cells like the proton exchange membrane (PEM) and the alkali fuel cell (AFC) will require some external reforming or gas removal system at the anode or cathode. On the other hand, a solid oxide fuel cell (SOFC) using a ceramic, like yttria-stabilized zirconia, as the electrolyte. Because conductivity is lower is solids, SOFCs need to operate at temperatures around 1500F which allows for internal reforming and thus more fuel flexibility. However, it’s not very likely an SOFC will be powering your car!
Why don’t I have a fuel cell in my home yet?!
While the underlying operating principle was developed in the early 1800’s, it has taken nearly 200 years to see the beginning of commercial application. As with many technical areas, timing is everything. In the late 1890’s, the emergence of the internal combustion engine dominated the energy generation landscape. It wasn’t until the 1950’s and 1960’s, when NASA began looking for a power source for the Apollo and Gemini space missions, that fuel cells began to be seriously considered. However, the technology was still expensive at a cost of nearly $600,000 per kW. It would take another 30 years before the automotive industry would begin to develop fuel cells for widespread distribution.
What is good old Uncle Sam doing about??
There are many challenges that remain to meet the DOE target of $30/kW. Funding in the area of fuel cells consists not only of improving performance of the system, but also hydrogen production, storage, and distribution, all of which limit the implementation of fuel cells. Funding through the Department of Energy has varied over the last 10 years. After peaking in 2008 with over $200 million, requested funding for next fiscal year is $100 million. Some funding programs have worked to engage multiple players in the research and development space. The Solid State Energy Conversion Alliance (SECA) began in 1999 and aimed to establish a collaboration between the federal government, private industry, academic institutions and national laboratories. This past year, the Advanced Research Projects Agency – Energy (ARPA-E) has solicited proposals for distributed energy generation technologies and set high technical goals for multi-functional solid oxide fuel cell systems that are a combination of storage (traditionally batteries) and fuel cells (traditionally only conversion).
While some companies have been emerged in the fuel cell space, there still exist sizable barriers to entry for many different market segments. But like many other technologies, it will most likely have a place in a diverse energy generating future.
If you are interested in some more resources, make sure to check out: https://energyclub.gatech.edu/files/2014/08/Fuel-Cell-Fundamentals.docx
The views expressed in this article are solely those of the author. There is no implied endorsement of ideas or concepts by the Energy Club or the Georgia Institute of Technology.